Sound emanates from a sound source at various rates and in varied directions, in relation to numerous characteristics associated with the sound source, the sound itself, and the environment in which the sound source is in. Sound results from a quickly varying pressure wave travelling through a medium, such as air. As sound travels through air, the air (at atmospheric pressure) varies periodically. The number of pressure variations per second is referred to as the frequency of sound, typically measured in Hertz (Hz) and defined as cycles per second.
Sounds having higher frequencies yield a higher-pitched sound to a listener or detector. For instance, sounds produced by percussion drums typically have much lower frequencies than those produced by flutes. Acoustic instruments in a string section of an orchestra may typically be one of a violin, viola, cello, and double bass, each of which produces its own sound at varying frequencies where overlap may also occur. These instruments may be difficult to hear over electronic sound sources or in an environment having high decibels noise for instance. However, in an orchestral environment, the sounds that emanate from these instruments are often quite discernible from the other instruments in the orchestra, particularly during a performance in an acoustically-oriented venue.
Since sound in acoustic instruments is the product of air pressure created by vibrations of the string, where the strings themselves are inefficient air movers, the design of the body of these instruments is purposeful to act as an amplifier. The body design is thereby able to boost the vibration, air pressure and sound intensity over a lone vibrating string. In such design, the strings are in communication with and vibrate across a bridge with the instrument where the body acts to amplify a suited range of appropriate frequencies which are generated by the vibrating strings. Sound, in relation to the sound source, the type of sound generated, and the environment of the sound source, may then be heard or detected in further relation to the sensitivity of the detector.
However, each part of each instrument's body, in relation to its shape, composition, size, etc., may resonate at different frequencies such that both the tonal character and radiation pattern of the instrument will vary considerably, particularly with frequency. It is recognized that the average polar responses of the violin and cello vary at a range of different frequencies; it is further understood that such instruments also emanate sound in differing ways, where for instance though a majority of sounds comes from the top or front of the instrument, the emanation is dependent on the instrument itself.
Therefore, what is desired is an approach to accurately determine a reference sound source position in relation to one or more targeted characteristics of one or more sound sources in a specific environment, where preferably, once the reference sound source position is determined, further visual indicia and stimuli can be aligned with the reference location to further engage and create viewer benefit.